The World of HarmonyOS Programming: Comprehensive ArkTS Development Cases and Best Practices

This article aims to deeply explore the technical details of the Huawei HarmonyOS Next system (up to API 12 as of now), and is summarized based on actual development practices. It mainly serves as a vehicle for technical sharing and communication. Mistakes and omissions are inevitable. Colleagues are welcome to put forward valuable opinions and questions so that we can make progress together. This article is original content, and any form of reprint must indicate the source and the original author.

Introduction: A Comprehensive Guide to Building Complex Applications

After mastering the basic knowledge and advanced features of ArkTS, it's time to apply what we've learned to actual projects and build a complex and efficient HarmonyOS application. This article will integrate all the knowledge points from the previous articles and guide you through a complete application development process, from design concepts to code implementation, and then to performance tuning. Each step reflects best practices.

Key Points

The Complete Application Development Process Combining Asynchronous Concurrency, UI, and I/O Operations

Process Details:

• Requirement Analysis: Clearly define the core functions of the application, analyze user scenarios, and determine performance and user experience goals.
• Architecture Design: Select an appropriate architecture pattern (such as MVVM, MVC), and plan module division and responsibility allocation.
• Concurrency Design: Determine which operations need to be processed in parallel, how to manage threads using TaskPool, and how to avoid race conditions and deadlocks.
• UI Design: Design the user interface to ensure a smooth user interaction experience, while handling communication between the UI thread and the worker threads.
• I/O Operations: Optimize file and network I/O to ensure efficient and safe data reading and writing. ##### Performance Tuning and Best Practices Tuning Strategies:
• Code Optimization: Avoid unnecessary object creation, use caching, and reduce memory allocation.
• Asynchronous Optimization: Use asynchronous programming reasonably to reduce thread blocking and improve response speed.
• Resource Management: Allocate and release resources reasonably to avoid memory leaks. Best Practices:
• Code Review: Conduct regular code reviews to ensure code quality.
• Performance Testing: Monitor application performance through performance testing tools and promptly identify bottlenecks.
• Continuous Integration: Establish an automated testing and deployment process to ensure code quality and application stability. ##### Code Organization and Modular Design Modular Principles:
• Single Responsibility: Each module is responsible for only one function to reduce the coupling between modules.
• Reusability: Design reusable modules and components to improve development efficiency.
• Maintainability: The interfaces between modules are clear, easy to understand, and maintain. #### Comprehensive Application Example The following is a comprehensive application example combining technologies such as UI, TaskPool, and asynchronous locks:

import { TaskPool, asyncLock, deserialize, serialize } from '@ArkTS/system';
import { UIComponent, Event } from '@ArkTS/ui';
class DataProcessor {
    // Logic for processing data
}
class MainUI extends UIComponent {
    private dataProcessor: DataProcessor;
    constructor() {
        super();
        this.dataProcessor = new DataProcessor();
    }
    @Event
    loadData() {
        TaskPool.dispatch(async () => {
            const data = await this.fetchData();
            const processedData = await this.processData(data);
            this.updateUI(processedData);
        });
    }
    private async fetchData(): Promise<string> {
        // Asynchronous data retrieval
    }
    private async processData(data: string): Promise<any> {
        // Process data using asynchronous lock
        return asyncLock.lock(async () => {
            const deserializedData = deserialize(data);
            const result = this.dataProcessor.process(deserializeData);
            return serialize(result);
        });
    }
    private updateUI(processedData: any) {
        // Update UI
    }
}
const mainUI = new MainUI();
mainUI.loadData();

Application Performance Tuning Suggestions and Examples

Tuning Suggestion	Description	Example Code
Use Caching	Avoid repeated calculations and data retrieval	const cache = new Map();
Asynchronous I/O	Use asynchronous methods to read file and network resources	async function readFileAsync() {...}
Avoid Global Variables	Reduce the use of global variables to avoid naming conflicts and state management issues	class LocalState {...}
Limit Thread Numbers	Use TaskPool to limit the number of concurrent threads to prevent excessive resource consumption	TaskPool.setThreadCount(4);
Code Splitting	Split the code into multiple modules and load them on demand	import('./module').then(module => {...})

Summary

Through the comprehensive cases and best practices in this article, you should be able to master how to apply the advanced features of ArkTS to actual HarmonyOS application development. From design to implementation, and then to performance tuning, each step requires careful planning and continuous practice. Hope this article can provide you with clear guidance and assistance, allowing you to make further progress on the path of HarmonyOS application development.